A number of combs and brushes are known to deliver a medication to skin surfaces. They are combs with hollow interior chambers in a backbone that holds a liquid medication and tines that are hollow allowing for the liquid to pass through tines either in a comb or amongst the bristles of a brush. These combs and brushes carry the risk of self contamination due to spillage, contamination of the environment, less control over dosage as it is affected by size of hole and temperature and the majority, if any, are not biodegradable. Prior art devices have been liquid dispensing devices.
Uniform delivery of the medications or concoctions has not been found to be effectively controlled by prior art devices. In some, the liquid merely flows out of openings in a comb at a rate determined by the size of the openings and characteristic, such as viscosity of the liquid, under the influence of gravity. Others utilize pressure at a reservoir where the liquid is applied periodically by a squeeze bulb or continuously from an external source supplying liquid through a tube or hose. Some comb like devices involved complicated valves and other controls which fail and impair the operation of the comb, making them less than satisfactory.
The primary problem with prior known dispensing devices in the form of a comb is that the flow of the liquid through the teeth and onto the scalp, by its nature, depended upon gravitational forces present when the comb (or brush) is used or upon pressure in the reservoir.
Such prior devices do not allow effective application of a liquid or medication to areas of, for example, an animal in which the comb or brush would not be held in an upright position, for example, in grooming the underside of the animal. When the devices were held in an upside-down or sideways position, liquid dispensing would be impacted by gravity and a lack of uniform delivery would be the consequence. Most of the liquid flowed within the chamber to the backbone of the comb so that a non-uniform delivery of liquid with medications (example flea applications) occurs with less than an ideal amount of medication being applied to the animal.
Also a major problem with dispensing devices heretofore known is that the flow of the liquid is generally not uniform onto the receiving surface. In U.S. Pat. No. 4,057,091 for example, a “metered” liquid flow was determined primarily by gravity so that the liquid application is maximized for areas in which the comb teeth are pointed essentially downwardly, but flow is zero in areas in which the comb teeth must be pointed upwardly to reach the application area.
U.S. Pat. No. 2,170,550 shows a comb utilizing absorbent pads in the tips of its teeth which serve to apply the liquid directly to a scalp. Cover air-locks the liquid within the backbone and teeth of the comb to prevent the liquid from pouring out through the teeth tips at an uncontrolled speed by means of capillary action of the pads. However, this device does not obviate the problem of the need for continuance of the flow of the liquid when the device is utilized in a non-upright position. When this device is held in an upside-down or sideways position, the liquid would not reach the absorbent pads in the tips of the teeth in order for the liquid to be dispensed.
Often it is desired to apply liquid to the length of hairs as well as to the scalp. Devices heretofore known have not been entirely successful in accomplishing this result. Previous attempts to produce a comb which would perform regardless of orientation are described in U.S. Pat. No. 2,376,065 where a bulb in the handle is required and U.S. Pat. No. 3,754,577 where the liquid is supplied from an extended hose. The attempts to apply medication grooming aids or cleansing agents have been the subject of many patents all of which have been unsatisfactory in one respect or another.